Javad Farhoudi

Javad Farhoudi
University of Tehran | UT · Department of Irrigation and Reclamation Engineering

Professor (full)

About

94
Publications
30,157
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517
Citations
Introduction
Javad Farhoudi, Distinguished Professor of hydraulic structures and river engineering, Department of Irrigation and Reclamation Engineering,University of Tehran. He received his Ph.D. in Hydraulic Structures from Southampton University, UK in 1979. He has many published papers in national and international journals and international conferences. His main field of research interests focused on scouring and pressure fluctuation encountered with stilling basins as well as flow measuring structures.

Publications

Publications (94)
Article
This paper describes the hydraulic characteristics of flow through a sluice gate over a broad-crested weir with a fixed upstream ramp slope of 1:2 and downstream ramp slopes of 1:2, 1:3, and 1:4. A relationship was proposed to determine the contraction coefficient of the flow passing through the gate, under free-flow conditions, in which the averag...
Article
Overshot gates are used as a flow measuring device to fix the upstream water level. Flow through the overshot gates under submerged conditions often has many problems, mainly due to the need to measure the tail-water depth. In this research, the application of the brink depth, instead of tail-water depth, has been selected to overcome this problem....
Article
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Dam removal is one of the methods of restoring the river ecosystem. In the present study, the removal of the Voshmgir Dam on the Gorganrud River, Iran, was considered, because of the high volume of sediment deposition in the reservoir and the loss of its useful life. Three scenarios were selected for the removal of the dam: 1- complete removal; 2-...
Article
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One of the structures for controlling and measuring flow in open channels are the sluice gates. In this study, to estimate the outflow from the sluice gates, the existing relationships for orifices evaluated theoretically and experimentally. A new method was established for estimating the contraction coefficient and energy loss coefficient under fr...
Article
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This paper discusses the capability of Guo et al.'s (2021) equations to determine the discharge of radial gates under submerged flow conditions. It was concluded that Guo et al.'s (2021) equations are associated with error reduction compared to the Incomplete Self-Similarity (ISS) theory and the calibration method. However, it does not have a signi...
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Radial gates are common structures in irrigation projects. This paper presents some theory-based equations for explicit estimation of the discharge from a radial gate under free and submerged flow conditions using energy and momentum (E-M) principles. The proposed equations were calibrated using extensive experimental data collected from the litera...
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n many applications, the adjustment of a gate opening to a specific value is crucial for the passage of a defined outflow or to maintain an upstream water level that serves upstream turnouts. Previous work used trial-and-error and interpolation methods to calculate the opening of sluice gates. This study concentrates on the development of a way to...
Article
The most widely used method of flushing of reservoirs is to remove the deposited sediment through the bottom outlets. The size and shape of gates affect the outflow volume of water, the volume of removed sediments, and flushing efficiency. The purpose of this study is to investigate the effect of the area, number and shape of the bottom outlet gate...
Article
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In this study, the flow through a simple low-cost flume constructed using two semi-cylinder contractions on either side of a rectangular channel was experimentally investigated. In practice, these flumes may operate under free- or submerged-flow conditions depending on the downstream flow depth. To reliably estimate the flume discharge, free- and s...
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Introduction In practical applications, for instance, at the downstream of hydraulic structures, in some cases the width of the basin may be larger than the upstream supercritical flow (sudden expansion in flow section). In such cases, an expanding hydraulic jump with symmetrical or asymmetrical shape will be developed at the downstream. Under the...
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In the original paper, the authors developed Eqs. (7), (11), and (12) to determine the discharge of the central baffle flume (CBF) by means of dimensional analysis and self-similarity. Also, Eq. (17) was developed based on the energy conservation approach. In Eq. (17), E 1 is a function of Q. Thus, the discharge should be determined through the tri...
Article
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One of the most commonly used devices for flow measurements in open channels is the flume, in which the flow velocity increases due to the lateral contraction, raising the bottom of the channel, or a combination of both them. SMBF is a flume with the above mentioned properties, having two semi-cylinders on the side walls of the channel that contrac...
Conference Paper
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River Geometry file is the most critical input for flood modelling by utilizing the hydraulic models. As water flows within the river, hydraulic parameters of flow, such as Inundated Extents, Velocity and Water Surface Elevation (WSE) are determined. Due to a considerable outlay of time and money for providing the surveyed topography maps, it is es...
Conference Paper
One of the factors in changing the morphology of rivers and its impact on downstream rivers is dams. Today, one of the ways to revive river ecosystems is to remove the dam. This article discusses the indicators that need to be considered when deciding to remove a dam. These indicators include physical, ecological, chemical, social and economic indi...
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A fully three dimensional hydrodynamic implicit numerical algorithm has been proposed for simultaneous simulation of fluid density variation and water table gradient in saturated porous media. Unlike the most of the performed researches that primarily restricted to solute transport simulation in confined or unconfined aquifers without proceeding to...
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A three dimensional coupled numerical model has been developed for incompressible density-driven free surface and saturated porous media flows. For free surface, a time-averaged Navier-Stokes equation has been used whereas Darcy's law has been utilized in porous media flow. The algorithm has been based upon a staggered finite volume scheme on a Car...
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A 2D hydrodynamic finite volume model has been proposed for simultaneous simulation of free surface and saturated porous media. The Governing equations of the former are 2D averaged in a unit width of Navier-Stokes, whereas that of the latter are Darcy law. An efficient, simple and stable algorithm has been proposed to track the surface elevation i...
Article
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Most of the previous studies related to radial gates are focused on the estimation of discharge from the gates as a flow measurement structure. However, determination of the gate opening for passing a certain value of the discharge is rarely considered in previous studies as a regulator structure. The present work presents some theoretical equation...
Conference Paper
In addition to the use of spillways with radial gate with a short height at regulating dams, they are used in the body of large reservoir dams and at the lower levels for flushing the sediments or regulating the flow at the outlet. At the earth and rockfill dams, the spillway is not a part of the dam and it is provided on either of the banks of the...
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Local scour downstream of hydraulic structures is one of the critical phenomena, which has absorbed a vast amount of interests by researchers. The designers of hydraulic structures, particularly, spillways try to utilize proper means to minimize the consequences of excess energies downstream of such structures which usually tend to erode their imme...
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Stepped spillways are employed to reduce excess energy encountered with exiting flow from high hydraulic structures. Study of local scour evolution downstream of stepped spillways wilt therefore, provide information to required get benefits from these structures to minimizes the scour hole dimensions. This paper provides the results of 67 experimen...
Article
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In recent years, considerable accomplishments were devoted for developing non hydrostatic models for simulation of water level in open channel flows. The main constraint to develop such models, arises from true definitions of water surface boundary condition. Some costly techniques such as VOF and MAC are used for these purposes. These techniques a...
Article
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Discharge measurement by sluice gates is one of the classical issues in hydraulic engineering. Based on the energy conservation relation, this study presents a novel method for estimating the discharge coefficient of sluice gates under free and submerged flow conditions. This method gives the discharge coefficient of sluice gates only as a function...
Article
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Circular-crested weirs are overflow structures with a reasonably high discharge coefficient, compared with that of sharp-and broad-crested weirs. In this study, combining the potential flow around a circular cylinder and the free vortex flow, to determine the discharge coefficient and velocity distribution simulated flow over circular-crested weirs...
Conference Paper
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یکی از روش¬های کلاسیک جهت اندازه¬گیری دبی جریان در شبکه¬های آبیاری و زهکشی، ایجاد یک مقطع کنترل و توسعه روابط دبی-اشل بواسطه احداث یک سازه هیدرولیکی در مسیر عبور جریان می¬باشد. سازه سرریز-دریچه، تیغه¬ی قائمی است که با وجود یک بازشدگی نسبت به کف کانال، امکان عبور توام جریان از لبه فوقانی آن به صورت سرریز و خروج جریان از بازشدگی پایین¬دست را فراهم می...
Article
Full-text available
This study presents some theoretical relationships to estimate the discharge from various types of radial gates under free and submerged flow conditions. These equations which based on energy and momentum approaches were calibrated by means of a large number of available experimental records retrieved from other work conducted on three types of rad...
Article
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In this paper, scour profiles downstream of adverse stilling basins due to the submerged jet issuing from a sluice gate, were investigated. Experiments were conducted in a wide range of sediment sizes, incoming flow Froude numbers, tailwater depths, length and slope of stilling basin. The results showed that the scour profiles at any bed slope are...
Conference Paper
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The present paper is concerned with experimental observations of flow properties and bedload sediment transport in the main channel of an asymmetric compound channel, roughened with cylindrical elements as vegetation on the floodplain. The observations confirm previous experiments that roughening the floodplain shift the maximum streamwise velocity...
Article
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The development of an enhanced approach for the use of radial gates as flow measurement structures is important in irrigation networks. In this study, new theoretical relationships were developed to estimate the discharge coefficient (Cd) for a single radial gate with three different sills, at free and submerged flow conditions. These equations wer...
Article
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A fully developed turbulent regime is considered as a specific case of non-Darcy flow and an analytical approach has been developed to determine normal depth, water surface profile and seepage discharge of the flow through coarse porous medium in steady condition. The results of a laboratory rock drain having 6.4 m length, 0.8m height and 0.8m widt...
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Because of the complexity of the physical processes in the vicinity of the hydraulic structures due to the separation of the flow, traditional methods for for prediction of maximum scour depth downstream of hydraulic structures are mostly based on empirical approaches. Hence, only a few theoretical works have been reported to study this phenomenon....
Article
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This paper is focused on local scour downstream of adverse stilling basins where a submerged wall jet issued from a sluice gate. Experiments were conducted in a wide range of Froude numbers, grain sizes, tailwater depths, and stilling basin slopes. The results showed that the scour profiles at any bed slope follow shape similarity. However, the lon...
Article
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In this paper, an analytical solution to solve 1-D partial differential equation is presented for fully developed turbulent flow through highly permeable sloping deposited porous medium. The present solution will be applicable for a wide range of slopes varying from zero to relatively steep slopes. To confirm the solution, the analytical results ha...
Article
This paper describes the results of experimental work in a circular flume and a reactor device to show the role and importance of flow velocity, sediment movement type and concentration in the kinetic adsorption and transport of cadmium in both bed and suspended load conditions. The results show that the rate of adsorption is directly connected wit...
Article
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In this research, the adverse hydraulic jump formed in a gradually expanding stilling basin of rectangular cross section is investigated both theoretically and experimentally. The experiments were conducted in a specially designed model for a wide range of bed slopes and diverging angles of the basin walls in addition to classic jump for a wide ran...
Article
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Sluice and radial radial gates are common devices used for flow control in hydraulic structures. This paper demonstrates the variation of the contraction coefficient of sluice gates and three types of radial gates (namely, Hard-Rubber, Sharp and Music Note gates) by using Energy and Momentum Equations (EMEs). This paper presents a novel method for...
Article
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Hydraulic jump on adverse stilling basin is an unstable phenomenon which causes some complexities in controlling of the jump. This paper considers the stability of free hydraulic jump on adverse stilling basins from a theoretical point of view. A minimum value of upstream Froude number is needed to produce the free hydraulic jump on adverse stillin...
Article
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The present work demonstrates the characteristics of flow from sluice gates under free and submerged flow conditions using Energy and Momentum Equations (EMEs). The experimental data was used from the research works reported by different investigators to calibrate the proposed equations. An equation for estimation energy loss factor of sluice gate...
Article
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The paper reports the characteristics of free and submerged outflow from sluice and radial gates in which both energy and momentum equations together with experimental data of several researchers are used. An equation has been given to approximate the energy loss of the gate along with its application in improving the accuracy of discharge coeffici...
Article
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This research is focused on local scour downstream of adverse stilling basins where the flow jet was issuing from a submerged sluice gate. Totally, 233 tests were performed and 3262 scour profiles were recorded in a wide range of Froude numbers, sediment grain sizes, tailwater depths, stilling basin’s length and bed slope. The results showed that t...
Article
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The paper describes the evolution of local scour hole downstream of an adverse stilling basin. The research was conducted using a wide range of Froude number, sediment size, tailwater depth, length and slope of stilling basin. The maximum depth of scour and its distance from the stilling basin attained 87.5% in the first 24 hours and 86.3% when the...
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The present paper would discuss the four linear regression of kinetic model of pseudo second order to describe the adsorption phenomenon. The adsorption parameters have been estimated by means of nonlinear method of pseudo second order as well as four linear regression methods are assessed. The results showed that, the nonlinear method of pseudo se...
Article
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The discharge coefficient of sluice gates in free and submerged conditions plays an important role in determining the flow rate past such structures. The effects of relative gate opening and submergence ratio have been widely considered by several investigators, mainly based on experimental work. Most of this work, however, lacks an analytical appr...
Article
In this experimental study, the effect of suspended sediment concentration on the characteristics of a submerged hydraulic jump in a rectangular channel has been investigated, based on the sediment concentrations of 0.43%-16.15% and jet Froude numbers were in the range of 1.9-5. Two grain sizes, 0.15 and 0.03 mm (ρs=2.65 g/cm3) have been used in th...
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The hydraulic characteristics of flow over rectangular broad-crested weirs with varying upstream slopes were experimentally studied. A series of laboratory experiments was performed to investigate the effects of changing upstream slopes from 90º to 75º, 60º, 45º, 30º, 22.5º, 15º, and 10º on the flow surface pattern, discharge coefficient values, ap...
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This paper presents the results of experimental study that was accomplished in a vortex settling chamber to observe the flow structures. A polar grid of data accusation was designed to trace the velocity characteristics of the flow. An ADV three dimensional velocity measuring equipment was utilized. The experiments were conducted under four differe...
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This paper presents the findings of an experimental study on the three-dimensional turbulent flow field in vortex settling basin. An ADV (Acoustic Doppler Velocity Meter) were used to catch 3D velocitycomponents inside the basin. Detailed measurements of time-averaged velocity components, turbulent intensity components and turbulent kinetic energy...
Data
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This paper reports on a set of laboratory experiments involving a layout that is common in irrigation diversion works. The layout involves a lateral intake channel with a diversion dam, positioned to allow the flow to be controlled and managed. Based on experimental measurements and observations, the effect of diversion angle (ranging from 90 to 12...
Article
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The paper presents the results of an investigation conducted in a vortex chamber to observe flow structure as well as extraction efficiency. During the experiments, various flow discharges were employed with high flow entrance velocities. Three sizes of sediment were fed at three different rates. It was observed that the increase in the flow and se...
Article
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The effect of bed-load transport on flow resistance of alluvial channels with undulated bed was experimentally investigated. The experiments were carried out in a tilting flume 250mm wide and 12.5m long with glass-sides of rectangular cross-section and artificial dune shaped floor that was made from Plexi-glass. Steady flow of clear as against sedi...
Article
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In the present study, the effect of suspended load transport on the characteristics of a hydraulic jump in a rectangular channel was investigated experimentally. Sediment concentration and initial Froude numbers in the range 0·42–16·15% and 2·5–8, respectively, were considered. Two grain sizes, 0·15 and 0·03 mm, were used in the experiments. Hydrau...
Article
Distribution of velocity in channel is one of the most parameters for solution of hydraulic problems. Determination of energy coefficient, momentum and distribution of sediment concentration depend on distribution of velocity profile. The entropy parameter of a channel section can be determined from the relation between the mean and maximum velocit...
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Problem statement: Cluster microforms are a type of small scale bed-form found in the surface layer of some gravel bed rivers. These bed-forms are comprised of discrete, organized groupings of particles that sit above the average elevation of the surrounding bed. As part of the structural organization of the bed, clusters are believed to impact the...
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s) to photocopy or make single electronic copies of the paper for their own personal use, including for their own classroom use, or the personal use of colleagues, provided the copies are not offered for sale and are not distributed in a systematic way outside of their employing institution. ABSTRACT The local scour phenomenon in the vicinity of br...
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Geometry of the chute blocks in stilling basins plays a significant role in size and type of these structures. One of the most influencing factors in the design of the blocks is the fluctuating pressure which may cause fatigue on the blocks. Despite investigations conducted by many researchers, there is not enough information about the pressure flu...
Article
The development of local scour holes downstream a hydraulic jump type flow in the passage of time shows certain geometrical similarities which may be expressed by relevant parameters. The present paper attempts to explain the similarity existing either in the process of scour or in the profiles that the scour holes follow downstream of hydraulic ju...